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Wilga 2006 8 TCP/IP stack First solution: usage minimalized TCP/IP stack with TCP, but camera is based on 8051 microcontroller (slow) and FPGA A second: giving up TCP, only UDP protocol which is very simple Used ethernet controller in the camera automatically calculates not only CRC of ethernet packets but checksums of IP, TCP and UDP protocols in their header!

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Wilga 2006 10 UDP limitations Advantages: One from plenty UDP ports under one IP Optional data checksum available Disadvantages: UDP datagram does not ensure receiving one by recipient A sequence of received packets can be accidental and depends on network traffic

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Wilga 2006 11 NUDP advantages Simple sensor network model, simplicited camera controller (everything in driver) Achieved packet receiving control by cameras acknowledgements It allows to save an order of packets There is possible retransmission of lost packets Close to compatibility with USB commands structure in EP1

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Wilga 2006 14 Types of NUDP packet 0 – command, it is starting from number field 4 – set a 16-bits register (RFU) 5 – read a 16-bits register (RFU) 6 – retransmission of RAW data packet 7 – transmission of RAW data packet, it is never acknowledged and generated by camera only Other numbers of type are reserved (RFU)

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Wilga 2006 18 Simulator and driver Linux system was chosen naturally NUDPSIM simulator was created for making and testings a new driver faster before camera with Ethernet was made For documentation and idea of the NUDP protocol checking programmers of the driver have not seen a source code of the simulator

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Wilga 2006 19 Results Camera with the driver testings Ethernet network infrastructure: 1Gbit/s Achieved performance: about 100Mbits/s Under Windows all packets were received Under Linux not, a feasible reason is the driver which is not a part or module of the kernel; some packets are losing between layers (kernel UDP timeout), even after debugging off The transfer depends on a network traffic – the loading has an important influence

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Wilga 2006 21 Summary USB was maintained next to Ethernet Some commands from USB were given up in the NUDP implementation (eg. flashing) Main aims were achieved but it will be checked in longer period of the time in practice The future: an implementation a TCP protocol by NIOS usage (Altera core) at FPGA chip and a RTOS